The invention relates to the field of electronic reproduction technology for multi-colored printing and relates to a method of simulating a multi-colored reproduction on a color monitor in order to execute a color evaluation and color correction of the anticipated printing result before the actual printing process. The invention also relates to a circuit arrangement referred to as a color viewing apparatus.
In the electronic reproduction of color originals, three primary color value signals, which are a measure for the color components red, green and blue of the scanned picture elements, are acquired in a color scanner by point-by-point and line-by-line trichromatic scanning of the original and opto-electronic conversion of the scan light. A color correction computer corrects the measured color value signals and generates four color separation signals for the color separations "yellow", "magenta", "cyan", and "black" in the case of four-color printing. During printing, the color separation signals indicate the required quantities of yellow, magenta, cyan, and black ink. The printing forms for printing are produced from the color-corrected separation signals. The superimposed printing of the printing forms inked with the four inks then occurs on the impression paper in impression printing presses.
Color viewing apparatus wherein the anticipated printing result is simulated by simulating the printing process on a color monitor, are in use in order to monitor the anticipated printing result even before the production of the printing forms, and in order to correct if necessary. So-called color converters or print simulation computers are employed for printing simulation, these converting the color separation signals into drive signals for the color monitor upon consideration of the print parameters such that the color picture of the monitor conveys the same chromatic impression as the anticipated multi-color printing on the impression paper.
U.S. Pat. No. 3,128,333, incorporated herein by reference, discloses a color converter in which the color separation signals are converted into corresponding drive signals for the color monitor by an analog signal processing. The known color converter, however, has the disadvantage that a reproduction quality of a multi-color reproduction, that is only averaged over the entire color space, can be achieved in the representation of party colors on the color monitor.